Steam generator



1945- J. P. B'ADENHAUSEN STEAM GENERATOR Filed Oct. 12, 1942 Patented Jan. 16, 1945 UNITED STATES PATENTjOFFl-C'E- 2,367,558 j J, "ff-j;-

9 STEAM GENERATOR v,

John Phillips Badenhausen, Philadelphia, Pa. Application October 12, 1942, Serial No.'461,674 I fiClaims. (o1. ne 165;

This invention relates to steam generators, and more particularly to the reclamation of combustible materials carried beyond the furnace or combustion chamber of the steam generator. In the operation of modern steam generators at high ratings and particularly in the operation of such steam generators which are provided with water cooled walls and forced draft, a very considerable quantity of solid material is, in many instances, carried beyond the combustion chamber. The solid material carried in the stream of gases passing from the combustion chamber of a steam generator stoker fired with anthracite coal, coke breeze and the like usually contains a considerable quantity of combustible material and the combustible content of this solid material may run from thirty to as high as seventy percent. The failure to burn this combustible material may seriously reduce the efiiciency of the steam generator and the collection of this material in the back passes of the steam generator or in other parts of the system may introduce operating difficulties.

Various attempts have heretofore been made to reclaim the unconsumed solid combustible material, but none of these have proven wholly satisfactory. For example, it has been proposed to return the unburned carbonaceous material to the combustion chamber with a relatively large quantity of air. The' condition of the solid material; particularly as to size, is such that it is diificult to retain it in the combustion chamber, particularly when introduced with large quantities of air. The quantity of air used, also, interferes with the proper operation of the furnace. It has also been proposed to collect and return the unburned solid materials to the coal bunker for mixing with the fuel and reintroduction into the furnace with the main supply of fuel. Where the unburned carbonaceous material has been added to the fuel in the bunker and introduced therewith, the condition of such material permits of its being picked up and carried away with the furnace gases prior to the completion of the combustion of the combustible content.

It is the principal object of the present invention to provide a steam generator, particularly for burning anthracite coal, coke breeze and the like, with adequate and satisfactory arrangements for reclaiming the unconsumed carbonaceous material carried beyond the combustion chamber. g

It is a further object of the present invention to provide a steam generator with adequatean rangements for the collection and transportation beyond the combustion chamber; .12:

It is a further object of the present invention to provide a steam generator for burning fanthrae. cite coal with improved arrangements 'for in'tr'oe ducing the unburned carbonaceous material. 1:;

It is a further objectiof theipresent'in'vention to provide, in a system of the character aforesaid; for the preparation of the unburned carbonaceous. material for reintroduction into the combustion chamber. i .I *i Other objects of the'invention willbeapparent from the annexed specification and claims.

The nature and characteristic features of the? invention will be more readily understood from: the following description, taken in connection with the accompanying drawing forming parthereof,inwhich: I J

Figure 1 is a diagrammatic view partly in eleva tion and part1y.in vertical section showing a"preferred embodiment of. the present invention;

Fig. 2 is a fragmentary vertical sectional view through a portion of thea'pparatus for preparing" the material for transport and combustion and Fig. 3 is a'fragmentary vertical sectional view showing the mannerof introduction'ofthe ma terial to be'reclaimed into the combustion chamber. 1' '5 It will, of course, be understood thatthefl de scription' and drawing' herein 1 are illustrative merely; and that various modifications and,

of the unburned carbonaceous:materialtcan ie changes may be made in thestructure "disclosed without departing from the spirit of-the-ihvention.

Referring more particularly tethe drawing; a steam generator is' show at 10; having '.a com; bustion chamber H with water? cooled walls; The side walls are; each lined with a' bank-of vertical steam" generating tubes" 1 manifeste at their lower ends to lower headers; f3 for thesupply of waterthereto and connected at their upper ends to headers '14. The headers M are in communication through banks of tubes IS with a transversely disposed horizontal'steam and water drum I 6. The front and top wall of the combustion chamber I l are lined with banksfo'f' steam generating tubes I! which extend from a header I8 to the steam and water drumlSZQThe rear wall of the combustion chamber [I may beshaped to form an arch l9 'of refractory rnate rial sup; ported 0n and cooled a bank of steam gen a e b s. 0 .f bnii e d malb a er if! and to an interm ediate header {Zi Certain of the tubes 23 extending from thg; intermediate header 22 to the steamand waten drum [6' are exposed to the radianthe'at of combustion in 2 the combustion chamber l I and aid in supporting and cooling the rear wall of the combustion chamber. It will be noted that the furnace or combustion chamber and the steam generator are integral. A plurality of walls or bailles 24, 25 and 26 are provided to the rear of the .baflle at the tubes 23 and spaced to form a plurality of passes for the gases from the combustion chamber ll. One or moreoi the passes may-be provided with banks of steamgenerating tubes. such as thebank of tubes 21 which extends from the header 2l-to the steam and water drum l and a superheater: may also be provided. The rearmost pass may be provided with an economizer 30 connected tothe steam and water drum 15.

A coal bunker and a coal hopper 36 are provided for supplying fuel, preferably anthracite coal, to a stoker 31, such as a chain gratestoker,

and thereon to the combustion chamber -ll (11125158. are-prnvidedsiorreaulnting thezquantity of fuel delivered. iron the .3& onto the. chainjlz. .Pmmisinmismade at the rear end .offl-torthmdischargeof the asninto an ash hopper 8&- i'mm'wheme the same may be. dispomd oi in the. customary-manner The foregoing description of "thesteam genentorzis merelytby wayioi illustrationras the pres- V mtinvmtmm iiszxppllicabheito other 'typeszofsteam.

To the rear of the steam generator In a dust-or copendingapplicaflonot Lloyrdd- Hersh, filed. Oc-

tdrer 4, 1981,. $13,603, althoughv any other'mrmd;

The of the collector 40 "isconnmied' tmtlm makerot'an. induced drait fsmme-oirtletaside of the Ian. M being connected in the customary maxim m-natural! 42. The colleetint hoppemfl o! .theseparaior M isprererably cimnectcdxto a chamber toiwhichrthe collected solid carbonaceous material from the hopperlfl-is delivered .preierably'bygravity;

The: collected solid. carbonaceous materiailmaybetransimdl 20m thezhanibes 45' dry :form In. if desired: maybe given a suitable treatment admixturecm.fluentimrteriials.v desired iuel oil or. a like hydrocarbon. containing materiallzmay .lae-ndded to iacreoseethe-heat. value of the material. prior" to its-return to the furnace. 0r, :11 desiredotherxfluentmaterials,combustible a: wit-CW1, andinchidiogi water; which would. aid in. transportation of the material tothe combustion chamber Ll may be added inquantities such that the mobility of. the collected materialis increased. Forthis-pzmpose the cham- Ber 511133 vl'aepnovidedwithrone or more-spray iota-l6) for introducing. the. additive material-from a supply .pipe. 4.1.

The outlet 0t thechamber i5 is, provided. with apparatus to: the withdrawal or thelcollectedmaterial, withor. without. material For this purposes taperedscrew 5 0 is preferablyemployed for receiving the carbonaceousmaterial and compacting, the. same. At. the.- same time. some additional mixing: willLbeeflectedifLadditive. materials are introduced; Asuitable electric motor 5|. is provided. for driving thescrew: 50..

A pipe. 52? is connected to. the discharge. end. of

the screw for conveying the mobile material to the combustion chamber II. The screw 50 serves to force the prepared material along the pipe 52 for further use.

The discharge end of the pipe 52 may be disposed at; any desired location in the combustion chamber but preferably extends through one of the gates 38 at the central portion of the front end of the combustion chamber ll so that the fuel material is delivered into the middle of the bed, that is, intermediate. the upper surface of the green coal and the upper surface of the grate 31 at the entrance to the combustion chamber H.

The mode of operation will now be pointed out. Coal or other fuel, and particularly anthracite coal or coke breeze is delivered from the bunker 35 through the'hopper 36 and onto the grate 31 in the. usual manner, the quantity advancing on the grate 31 being controlled by the positioning of the gates 38. The movement of the grate 31 progressively advances the 111121. in the customary manner; through. an initial ignition-zone and a subsequent; combustion zone adiacent and-under the arch.- l-9, 'and. the ash' in. a'final ash. zone is advanced. and falls into the ash hopper 38. Air, supplied through. the: duct passes up through the: grate 31 and effects the combustion of the fuel on th grate 31 and. the. continued combustion. of the hotgases arising from thegrate 11.. The heat from the gases of combustion rising in the combustion chamber H and from the bunk illg. oi the fuel on. thegrate I1 is available for generating steamin the: banks of tube lining the walls of the combustion chamber H. The hot gases passirom the combustion chamber H and give up further quantities 01 heat to the water in thetubes 21 connected tothe steam and water drum l6 and to the water in the tubes: of the economizer. iMl.

The rising stream or gases from the grate 31 carries with it particles of. unconsumed solid material of: high. combustible content and this material is carried onwardly with the advancing stream. of gases and beyond the steam generator It The stream 01. gases with; its. solids content enters the-separator or collector 40- and the solids content is extracted and is collected in them]- looting hopper l3. From the. collecting hopper 43,v the solids pass into: the chamber 45. The screw- 59 continuously withdraws thecollectedmaterial .trom; the chamber 45 and compacts the samefor delivery. The screw 50 delivers the material through the: pipe 52 and. into the: midportion of the green. fuel entering the combustion chamber H on the grate I1 and intermediate the upper and. lower surfaces. of the.- iuel so that it is not readily carried upwardly with. the rising stream of. gases. The retumed material h blanketed and held for buming' by themain stream of fuel supplied to the combustion chamber I l on the grate 31.

The compaction of the solid unconsumed conbustible material permits oi the facile delivery of the same and the retention oithe same-ate location and in a conditionv for the burning of the combustible constituents. This is effected not only without. interierence with the proper functioning of the steam generator but in a man.- ner which increases the operative eiliciency of the steam. generator Hi.

When. additive materials are employed these are introduced through the spray nozzle 8 and. mixw'th thecollected solid material in the chamber 4.5. with further mixing. aided and. efiected and compaction also effected by the screw .50..

The added material supplied in the chamber 45, particularly if lacking in the lubricating qualities of hydrocarbons, is employed in quantities which will not decrease but preferably increase the mobility of the material upon compaction therewith. The transportation of the material from the chamber 45 and through the pipe 52 will be facilitated if the added material is of a quantity to give with compaction a consistency of mixture capable of flow under pressure through the pipe 52. The mixture is then delivered to the combustion chamber through the pipe 52 in the same manner as the collected dry material.

I claim:

1. In combination with a steam generator having a combustion chamber, a stoker for supplying low volatile fuel in a continuous bed to the combustion chamber for combustion, and means including a conduit for exhausting combustion gases from the combustion chamber, means in said conduit for separating from the exhaust combustion gases solid particles of combustible material carried beyond the steam generator in the exhaust combustion gases, means for compacting the separated combustible material in mobile form, and means including a delivery pipe intermediate the sides of the stoker for supplying said material with the low volatile fuel on the stoker between the upper and lower surfaces of the fuel bed on the stoker, whereby said solid material is retained by the fuel bed for combustion.

2. In combination with a steam generator having a combustion chamber, an endless stoker for supplying low volatile fuel to the combustion chamber and a conduit for exhausting combustion gases from the combustion chamber, a collector in said conduit forcollecting solid particles of carbonaceous material carried beyond the combustion chamber in the exhaust combustion gases, a mixing chamber to which the collected solid carbonaceous material is delivered from the collector, means for supplying a mobility increasing agent to said chamber for admixture with said material, and means for compacting said material and for delivering the compacted material to said combustion chamber for introduction with and retention by the fuel supply on said stoker.

3. In combination with a steam generator having a combustion chamber, an endless stoker for supplying low volatile fuel to the combustion chamber, and a conduit for exhausting combustion gases from the combustion chamber, a col lector in said conduit for collecting solid carbonaceous material carried beyond the combustion chamber in the exhaust combustion gases, a chamber to which the collected solid carbonaceous material is delivered from the collector, means for supplying water to said chamber for admixture with said material, a screw for compacting said material and advancing the same, and a delivery pipe above said stoker and receiving the compacted material from the screw for delivering the compacted material for introduction with and retention by the fuel bed on said stoker.

4. In combination with a steam generator having a combustion chamber and a conduit for exhausting combustion gases from the combustion chamber, means in said conduit for separating from the exhaust combustion gases particles of solid combustible material of low volatile content carried beyondthe combustion chamber in the combustion gases, a continuously movable endless stoker for supplying low volatile fuel in a continuous bed to the combustion chamber at the bottom thereof for combustion, and means for returning to said combustion chamber said solid combustible material intermediate the upper and lower surfaces of the fuel bed and with the low volatile fuel on said stoker for retention by said fuel, said last means including a delivery pipe extending over said stoker intermediate the sides thereof.

5. In combination with a steam generator having a combustion chamber, a conduit forexhausting combustion gases from the combustion chamber, means in said conduit for separating from the exhaust combusion gases solid particles of combustible material carried beyond the combustion chamber in the combustion gases, a continuously movable stoker of the endless type for supplying low volatile fuel in a continuous bed to the combustion chamber for combustion, means for adding a mobility increasing material to said separated solid combustible material, and means for returning to said combustion chamber said separated combustible material intermediate the upper and lower surfaces of the bed of low volatile fuel supplied by said stoker for retention by said fuel, said last means including a combustible material delivery pipe extending rearwardly over said stoker intermediate the sides thereof.

6. In combination with a steam generator having a combustion chamber and a conduit for exhausting combustion gases from the combustion chamber, means in said conduit for separating from the exhaust combustion gases solid particles of combustible material carried beyond the combustion chamber in the combustion gases, a continuously movable stoker of the endless type for supplying low volatile fuel in a continuous bed to the lowerpart of the combustion chamber for combustion, means for adding a mobility increasing and volatile supplying material to said separated solid combustible material, means for compacting the separated combustible material, and means for delivering the compacted combustible material and volatile supplying material to the combustion chamber with the fuel bed and intermediate the upper and lower surfaces thereof, said last means including a combustible material delivery pipe extending rearwardly over said stoker intermediate the. sides thereof.

JOHN PHILLIPS BADENHAUSEN. 

